David Zeuthen | 33bae49 | 2014-02-25 16:16:18 -0800 | [diff] [blame^] | 1 | // Copyright 2014 The Chromium OS Authors. All rights reserved. |
| 2 | // Use of this source code is governed by a BSD-style license that can be |
| 3 | // found in the LICENSE file. |
| 4 | |
| 5 | #include "update_engine/metrics.h" |
| 6 | |
| 7 | #include <string> |
| 8 | |
| 9 | #include <base/logging.h> |
| 10 | |
| 11 | #include "update_engine/constants.h" |
| 12 | #include "update_engine/clock_interface.h" |
| 13 | #include "update_engine/prefs_interface.h" |
| 14 | #include "update_engine/system_state.h" |
| 15 | #include "update_engine/utils.h" |
| 16 | |
| 17 | using std::string; |
| 18 | |
| 19 | namespace chromeos_update_engine { |
| 20 | |
| 21 | namespace metrics { |
| 22 | |
| 23 | // UpdateEngine.Daily.* metrics. |
| 24 | const char kMetricDailyOSAgeDays[] = "UpdateEngine.Daily.OSAgeDays"; |
| 25 | |
| 26 | // UpdateEngine.Check.* metrics. |
| 27 | const char kMetricCheckDownloadErrorCode[] = |
| 28 | "UpdateEngine.Check.DownloadErrorCode"; |
| 29 | const char kMetricCheckReaction[] = "UpdateEngine.Check.Reaction"; |
| 30 | const char kMetricCheckResult[] = "UpdateEngine.Check.Result"; |
| 31 | const char kMetricCheckTimeSinceLastCheckMinutes[] = |
| 32 | "UpdateEngine.Check.TimeSinceLastCheckMinutes"; |
| 33 | const char kMetricCheckTimeSinceLastCheckUptimeMinutes[] = |
| 34 | "UpdateEngine.Check.TimeSinceLastCheckUptimeMinutes"; |
| 35 | |
| 36 | // UpdateEngine.Attempt.* metrics. |
| 37 | const char kMetricAttemptNumber[] = "UpdateEngine.Attempt.Number"; |
| 38 | const char kMetricAttemptPayloadType[] = |
| 39 | "UpdateEngine.Attempt.PayloadType"; |
| 40 | const char kMetricAttemptPayloadSizeMiB[] = |
| 41 | "UpdateEngine.Attempt.PayloadSizeMiB"; |
| 42 | const char kMetricAttemptDurationMinutes[] = |
| 43 | "UpdateEngine.Attempt.DurationMinutes"; |
| 44 | const char kMetricAttemptDurationUptimeMinutes[] = |
| 45 | "UpdateEngine.Attempt.DurationUptimeMinutes"; |
| 46 | const char kMetricAttemptTimeSinceLastAttemptMinutes[] = |
| 47 | "UpdateEngine.Attempt.TimeSinceLastAttemptMinutes"; |
| 48 | const char kMetricAttemptTimeSinceLastAttemptUptimeMinutes[] = |
| 49 | "UpdateEngine.Attempt.TimeSinceLastAttemptUptimeMinutes"; |
| 50 | const char kMetricAttemptPayloadBytesOffset[] = |
| 51 | "UpdateEngine.Attempt.PayloadBytesOffset"; |
| 52 | const char kMetricAttemptPayloadBytesNeeded[] = |
| 53 | "UpdateEngine.Attempt.PayloadBytesNeeded"; |
| 54 | const char kMetricAttemptPayloadBytesDownloadedMiB[] = |
| 55 | "UpdateEngine.Attempt.PayloadBytesDownloadedMiB"; |
| 56 | const char kMetricAttemptPayloadDownloadSpeedKBps[] = |
| 57 | "UpdateEngine.Attempt.PayloadDownloadSpeedKBps"; |
| 58 | const char kMetricAttemptDownloadSource[] = |
| 59 | "UpdateEngine.Attempt.DownloadSource"; |
| 60 | const char kMetricAttemptResult[] = |
| 61 | "UpdateEngine.Attempt.Result"; |
| 62 | const char kMetricAttemptInternalErrorCode[] = |
| 63 | "UpdateEngine.Attempt.InternalErrorCode"; |
| 64 | const char kMetricAttemptDownloadErrorCode[] = |
| 65 | "UpdateEngine.Attempt.DownloadErrorCode"; |
| 66 | |
| 67 | // UpdateEngine.SuccessfulUpdate.* metrics. |
| 68 | const char kMetricSuccessfulUpdateAttemptCount[] = |
| 69 | "UpdateEngine.SuccessfulUpdate.AttemptCount"; |
| 70 | const char kMetricSuccessfulUpdateBytesDownloadedMiB[] = |
| 71 | "UpdateEngine.SuccessfulUpdate.BytesDownloadedMiB"; |
| 72 | const char kMetricSuccessfulUpdateDownloadOverheadPercentage[] = |
| 73 | "UpdateEngine.SuccessfulUpdate.DownloadOverheadPercentage"; |
| 74 | const char kMetricSuccessfulUpdateDownloadSourcesUsed[] = |
| 75 | "UpdateEngine.SuccessfulUpdate.DownloadSourcesUsed"; |
| 76 | const char kMetricSuccessfulUpdatePayloadType[] = |
| 77 | "UpdateEngine.SuccessfulUpdate.PayloadType"; |
| 78 | const char kMetricSuccessfulUpdatePayloadSizeMiB[] = |
| 79 | "UpdateEngine.SuccessfulUpdate.PayloadSizeMiB"; |
| 80 | const char kMetricSuccessfulUpdateRebootCount[] = |
| 81 | "UpdateEngine.SuccessfulUpdate.RebootCount"; |
| 82 | const char kMetricSuccessfulUpdateTotalDurationMinutes[] = |
| 83 | "UpdateEngine.SuccessfulUpdate.TotalDurationMinutes"; |
| 84 | const char kMetricSuccessfulUpdateUpdatesAbandonedCount[] = |
| 85 | "UpdateEngine.SuccessfulUpdate.UpdatesAbandonedCount"; |
| 86 | const char kMetricSuccessfulUpdateUrlSwitchCount[] = |
| 87 | "UpdateEngine.SuccessfulUpdate.UrlSwitchCount"; |
| 88 | |
| 89 | // UpdateEngine.* metrics. |
| 90 | const char kMetricFailedUpdateCount[] = "UpdateEngine.FailedUpdateCount"; |
| 91 | const char kMetricInstallDateProvisioningSource[] = |
| 92 | "UpdateEngine.InstallDateProvisioningSource"; |
| 93 | const char kMetricTimeToRebootMinutes[] = |
| 94 | "UpdateEngine.TimeToRebootMinutes"; |
| 95 | |
| 96 | void ReportDailyMetrics(SystemState *system_state, |
| 97 | base::TimeDelta os_age) { |
| 98 | string metric = metrics::kMetricDailyOSAgeDays; |
| 99 | LOG(INFO) << "Uploading " << utils::FormatTimeDelta(os_age) |
| 100 | << " for metric " << metric; |
| 101 | system_state->metrics_lib()->SendToUMA( |
| 102 | metric, |
| 103 | static_cast<int>(os_age.InDays()), |
| 104 | 0, // min: 0 days |
| 105 | 6*30, // max: 6 months (approx) |
| 106 | 50); // num_buckets |
| 107 | } |
| 108 | |
| 109 | void ReportUpdateCheckMetrics(SystemState *system_state, |
| 110 | CheckResult result, |
| 111 | CheckReaction reaction, |
| 112 | DownloadErrorCode download_error_code) { |
| 113 | string metric; |
| 114 | int value; |
| 115 | int max_value; |
| 116 | |
| 117 | if (result != metrics::CheckResult::kUnset) { |
| 118 | metric = metrics::kMetricCheckResult; |
| 119 | value = static_cast<int>(result); |
| 120 | max_value = static_cast<int>(metrics::CheckResult::kNumConstants) - 1; |
| 121 | LOG(INFO) << "Sending " << value << " for metric " << metric << " (enum)"; |
| 122 | system_state->metrics_lib()->SendEnumToUMA(metric, value, max_value); |
| 123 | } |
| 124 | if (reaction != metrics::CheckReaction::kUnset) { |
| 125 | metric = metrics::kMetricCheckReaction; |
| 126 | value = static_cast<int>(reaction); |
| 127 | max_value = static_cast<int>(metrics::CheckReaction::kNumConstants) - 1; |
| 128 | LOG(INFO) << "Sending " << value << " for metric " << metric << " (enum)"; |
| 129 | system_state->metrics_lib()->SendEnumToUMA(metric, value, max_value); |
| 130 | } |
| 131 | if (download_error_code != metrics::DownloadErrorCode::kUnset) { |
| 132 | metric = metrics::kMetricCheckDownloadErrorCode; |
| 133 | value = static_cast<int>(download_error_code); |
| 134 | max_value = static_cast<int>(metrics::DownloadErrorCode::kNumConstants) - 1; |
| 135 | LOG(INFO) << "Sending " << value << " for metric " << metric << " (enum)"; |
| 136 | system_state->metrics_lib()->SendEnumToUMA(metric, value, max_value); |
| 137 | } |
| 138 | |
| 139 | base::TimeDelta time_since_last; |
| 140 | if (utils::WallclockDurationHelper(system_state, |
| 141 | kPrefsMetricsCheckLastReportingTime, |
| 142 | &time_since_last)) { |
| 143 | metric = kMetricCheckTimeSinceLastCheckMinutes; |
| 144 | LOG(INFO) << "Sending " << utils::FormatTimeDelta(time_since_last) |
| 145 | << " for metric " << metric; |
| 146 | system_state->metrics_lib()->SendToUMA( |
| 147 | metric, |
| 148 | time_since_last.InMinutes(), |
| 149 | 0, // min: 0 min |
| 150 | 30*24*60, // max: 30 days |
| 151 | 50); // num_buckets |
| 152 | } |
| 153 | |
| 154 | base::TimeDelta uptime_since_last; |
| 155 | static int64_t uptime_since_last_storage = 0; |
| 156 | if (utils::MonotonicDurationHelper(system_state, |
| 157 | &uptime_since_last_storage, |
| 158 | &uptime_since_last)) { |
| 159 | metric = kMetricCheckTimeSinceLastCheckUptimeMinutes; |
| 160 | LOG(INFO) << "Sending " << utils::FormatTimeDelta(uptime_since_last) |
| 161 | << " for metric " << metric; |
| 162 | system_state->metrics_lib()->SendToUMA( |
| 163 | metric, |
| 164 | uptime_since_last.InMinutes(), |
| 165 | 0, // min: 0 min |
| 166 | 30*24*60, // max: 30 days |
| 167 | 50); // num_buckets |
| 168 | } |
| 169 | } |
| 170 | |
| 171 | void ReportUpdateAttemptMetrics( |
| 172 | SystemState *system_state, |
| 173 | int attempt_number, |
| 174 | PayloadType payload_type, |
| 175 | base::TimeDelta duration, |
| 176 | base::TimeDelta duration_uptime, |
| 177 | int64_t payload_size, |
| 178 | int64_t payload_bytes_downloaded, |
| 179 | int64_t payload_download_speed_bps, |
| 180 | DownloadSource download_source, |
| 181 | AttemptResult attempt_result, |
| 182 | ErrorCode internal_error_code, |
| 183 | DownloadErrorCode payload_download_error_code) { |
| 184 | string metric; |
| 185 | |
| 186 | metric = metrics::kMetricAttemptNumber; |
| 187 | LOG(INFO) << "Uploading " << attempt_number << " for metric " << metric; |
| 188 | system_state->metrics_lib()->SendToUMA(metric, |
| 189 | attempt_number, |
| 190 | 0, // min: 0 attempts |
| 191 | 49, // max: 49 attempts |
| 192 | 50); // num_buckets |
| 193 | |
| 194 | metric = metrics::kMetricAttemptPayloadType; |
| 195 | LOG(INFO) << "Uploading " << utils::ToString(payload_type) |
| 196 | << " for metric " << metric; |
| 197 | system_state->metrics_lib()->SendEnumToUMA(metric, |
| 198 | payload_type, |
| 199 | kNumPayloadTypes); |
| 200 | |
| 201 | metric = metrics::kMetricAttemptDurationMinutes; |
| 202 | LOG(INFO) << "Uploading " << utils::FormatTimeDelta(duration) |
| 203 | << " for metric " << metric; |
| 204 | system_state->metrics_lib()->SendToUMA(metric, |
| 205 | duration.InMinutes(), |
| 206 | 0, // min: 0 min |
| 207 | 10*24*60, // max: 10 days |
| 208 | 50); // num_buckets |
| 209 | |
| 210 | metric = metrics::kMetricAttemptDurationUptimeMinutes; |
| 211 | LOG(INFO) << "Uploading " << utils::FormatTimeDelta(duration_uptime) |
| 212 | << " for metric " << metric; |
| 213 | system_state->metrics_lib()->SendToUMA(metric, |
| 214 | duration_uptime.InMinutes(), |
| 215 | 0, // min: 0 min |
| 216 | 10*24*60, // max: 10 days |
| 217 | 50); // num_buckets |
| 218 | |
| 219 | metric = metrics::kMetricAttemptPayloadSizeMiB; |
| 220 | int64_t payload_size_mib = payload_size / kNumBytesInOneMiB; |
| 221 | LOG(INFO) << "Uploading " << payload_size_mib << " for metric " << metric; |
| 222 | system_state->metrics_lib()->SendToUMA(metric, |
| 223 | payload_size_mib, |
| 224 | 0, // min: 0 MiB |
| 225 | 1024, // max: 1024 MiB = 1 GiB |
| 226 | 50); // num_buckets |
| 227 | |
| 228 | metric = metrics::kMetricAttemptPayloadBytesDownloadedMiB; |
| 229 | int64_t payload_bytes_downloaded_mib = |
| 230 | payload_bytes_downloaded / kNumBytesInOneMiB; |
| 231 | LOG(INFO) << "Uploading " << payload_bytes_downloaded_mib |
| 232 | << " for metric " << metric; |
| 233 | system_state->metrics_lib()->SendToUMA(metric, |
| 234 | payload_bytes_downloaded_mib, |
| 235 | 0, // min: 0 MiB |
| 236 | 1024, // max: 1024 MiB = 1 GiB |
| 237 | 50); // num_buckets |
| 238 | |
| 239 | metric = metrics::kMetricAttemptPayloadDownloadSpeedKBps; |
| 240 | int64_t payload_download_speed_kbps = payload_download_speed_bps / 1000; |
| 241 | LOG(INFO) << "Uploading " << payload_download_speed_kbps |
| 242 | << " for metric " << metric; |
| 243 | system_state->metrics_lib()->SendToUMA(metric, |
| 244 | payload_download_speed_kbps, |
| 245 | 0, // min: 0 kB/s |
| 246 | 10*1000, // max: 10000 kB/s = 10 MB/s |
| 247 | 50); // num_buckets |
| 248 | |
| 249 | metric = metrics::kMetricAttemptDownloadSource; |
| 250 | LOG(INFO) << "Uploading " << download_source |
| 251 | << " for metric " << metric; |
| 252 | system_state->metrics_lib()->SendEnumToUMA(metric, |
| 253 | download_source, |
| 254 | kNumDownloadSources); |
| 255 | |
| 256 | metric = metrics::kMetricAttemptResult; |
| 257 | LOG(INFO) << "Uploading " << static_cast<int>(attempt_result) |
| 258 | << " for metric " << metric; |
| 259 | system_state->metrics_lib()->SendEnumToUMA( |
| 260 | metric, |
| 261 | static_cast<int>(attempt_result), |
| 262 | static_cast<int>(AttemptResult::kNumConstants)); |
| 263 | |
| 264 | if (internal_error_code != kErrorCodeSuccess) { |
| 265 | metric = metrics::kMetricAttemptInternalErrorCode; |
| 266 | LOG(INFO) << "Uploading " << internal_error_code |
| 267 | << " for metric " << metric; |
| 268 | system_state->metrics_lib()->SendEnumToUMA( |
| 269 | metric, |
| 270 | internal_error_code, |
| 271 | kErrorCodeUmaReportedMax); |
| 272 | } |
| 273 | |
| 274 | if (payload_download_error_code != DownloadErrorCode::kUnset) { |
| 275 | metric = metrics::kMetricAttemptDownloadErrorCode; |
| 276 | LOG(INFO) << "Uploading " << static_cast<int>(payload_download_error_code) |
| 277 | << " for metric " << metric; |
| 278 | system_state->metrics_lib()->SendEnumToUMA( |
| 279 | metric, |
| 280 | static_cast<int>(payload_download_error_code), |
| 281 | static_cast<int>(DownloadErrorCode::kNumConstants)); |
| 282 | } |
| 283 | |
| 284 | base::TimeDelta time_since_last; |
| 285 | if (utils::WallclockDurationHelper(system_state, |
| 286 | kPrefsMetricsAttemptLastReportingTime, |
| 287 | &time_since_last)) { |
| 288 | metric = kMetricAttemptTimeSinceLastAttemptMinutes; |
| 289 | LOG(INFO) << "Sending " << utils::FormatTimeDelta(time_since_last) |
| 290 | << " for metric " << metric; |
| 291 | system_state->metrics_lib()->SendToUMA( |
| 292 | metric, |
| 293 | time_since_last.InMinutes(), |
| 294 | 0, // min: 0 min |
| 295 | 30*24*60, // max: 30 days |
| 296 | 50); // num_buckets |
| 297 | } |
| 298 | |
| 299 | static int64_t uptime_since_last_storage = 0; |
| 300 | base::TimeDelta uptime_since_last; |
| 301 | if (utils::MonotonicDurationHelper(system_state, |
| 302 | &uptime_since_last_storage, |
| 303 | &uptime_since_last)) { |
| 304 | metric = kMetricAttemptTimeSinceLastAttemptUptimeMinutes; |
| 305 | LOG(INFO) << "Sending " << utils::FormatTimeDelta(uptime_since_last) |
| 306 | << " for metric " << metric; |
| 307 | system_state->metrics_lib()->SendToUMA( |
| 308 | metric, |
| 309 | uptime_since_last.InMinutes(), |
| 310 | 0, // min: 0 min |
| 311 | 30*24*60, // max: 30 days |
| 312 | 50); // num_buckets |
| 313 | } |
| 314 | } |
| 315 | |
| 316 | |
| 317 | void ReportSuccessfulUpdateMetrics( |
| 318 | SystemState *system_state, |
| 319 | int attempt_count, |
| 320 | int updates_abandoned_count, |
| 321 | PayloadType payload_type, |
| 322 | int64_t payload_size, |
| 323 | int64_t num_bytes_downloaded[kNumDownloadSources], |
| 324 | int download_overhead_percentage, |
| 325 | base::TimeDelta total_duration, |
| 326 | int reboot_count, |
| 327 | int url_switch_count) { |
| 328 | string metric; |
| 329 | int64_t mbs; |
| 330 | |
| 331 | metric = kMetricSuccessfulUpdatePayloadSizeMiB; |
| 332 | mbs = payload_size / kNumBytesInOneMiB; |
| 333 | LOG(INFO) << "Uploading " << mbs << " (MiBs) for metric " << metric; |
| 334 | system_state->metrics_lib()->SendToUMA(metric, |
| 335 | mbs, |
| 336 | 0, // min: 0 MiB |
| 337 | 1024, // max: 1024 MiB = 1 GiB |
| 338 | 50); // num_buckets |
| 339 | |
| 340 | int64_t total_bytes = 0; |
| 341 | int download_sources_used = 0; |
| 342 | for (int i = 0; i < kNumDownloadSources + 1; i++) { |
| 343 | DownloadSource source = static_cast<DownloadSource>(i); |
| 344 | |
| 345 | // Only consider this download source (and send byte counts) as |
| 346 | // having been used if we downloaded a non-trivial amount of bytes |
| 347 | // (e.g. at least 1 MiB) that contributed to the the |
| 348 | // update. Otherwise we're going to end up with a lot of zero-byte |
| 349 | // events in the histogram. |
| 350 | |
| 351 | metric = metrics::kMetricSuccessfulUpdateBytesDownloadedMiB; |
| 352 | if (i < kNumDownloadSources) { |
| 353 | metric += utils::ToString(source); |
| 354 | mbs = num_bytes_downloaded[i] / kNumBytesInOneMiB; |
| 355 | total_bytes += num_bytes_downloaded[i]; |
| 356 | if (mbs > 0) |
| 357 | download_sources_used |= (1 << i); |
| 358 | } else { |
| 359 | mbs = total_bytes / kNumBytesInOneMiB; |
| 360 | } |
| 361 | |
| 362 | if (mbs > 0) { |
| 363 | LOG(INFO) << "Uploading " << mbs << " (MiBs) for metric " << metric; |
| 364 | system_state->metrics_lib()->SendToUMA(metric, |
| 365 | mbs, |
| 366 | 0, // min: 0 MiB |
| 367 | 1024, // max: 1024 MiB = 1 GiB |
| 368 | 50); // num_buckets |
| 369 | } |
| 370 | } |
| 371 | |
| 372 | metric = metrics::kMetricSuccessfulUpdateDownloadSourcesUsed; |
| 373 | LOG(INFO) << "Uploading 0x" << std::hex << download_sources_used |
| 374 | << " (bit flags) for metric " << metric; |
| 375 | system_state->metrics_lib()->SendToUMA( |
| 376 | metric, |
| 377 | download_sources_used, |
| 378 | 0, // min |
| 379 | (1 << kNumDownloadSources) - 1, // max |
| 380 | 1 << kNumDownloadSources); // num_buckets |
| 381 | |
| 382 | metric = metrics::kMetricSuccessfulUpdateDownloadOverheadPercentage; |
| 383 | LOG(INFO) << "Uploading " << download_overhead_percentage |
| 384 | << "% for metric " << metric; |
| 385 | system_state->metrics_lib()->SendToUMA(metric, |
| 386 | download_overhead_percentage, |
| 387 | 0, // min: 0% overhead |
| 388 | 1000, // max: 1000% overhead |
| 389 | 50); // num_buckets |
| 390 | |
| 391 | metric = metrics::kMetricSuccessfulUpdateUrlSwitchCount; |
| 392 | LOG(INFO) << "Uploading " << url_switch_count |
| 393 | << " (count) for metric " << metric; |
| 394 | system_state->metrics_lib()->SendToUMA(metric, |
| 395 | url_switch_count, |
| 396 | 0, // min: 0 URL switches |
| 397 | 49, // max: 49 URL switches |
| 398 | 50); // num_buckets |
| 399 | |
| 400 | metric = metrics::kMetricSuccessfulUpdateTotalDurationMinutes; |
| 401 | LOG(INFO) << "Uploading " << utils::FormatTimeDelta(total_duration) |
| 402 | << " for metric " << metric; |
| 403 | system_state->metrics_lib()->SendToUMA( |
| 404 | metric, |
| 405 | static_cast<int>(total_duration.InMinutes()), |
| 406 | 0, // min: 0 min |
| 407 | 365*24*60, // max: 365 days ~= 1 year |
| 408 | 50); // num_buckets |
| 409 | |
| 410 | metric = metrics::kMetricSuccessfulUpdateRebootCount; |
| 411 | LOG(INFO) << "Uploading reboot count of " << reboot_count << " for metric " |
| 412 | << metric; |
| 413 | system_state->metrics_lib()->SendToUMA(metric, |
| 414 | reboot_count, |
| 415 | 0, // min: 0 reboots |
| 416 | 49, // max: 49 reboots |
| 417 | 50); // num_buckets |
| 418 | |
| 419 | metric = metrics::kMetricSuccessfulUpdatePayloadType; |
| 420 | system_state->metrics_lib()->SendEnumToUMA(metric, |
| 421 | payload_type, |
| 422 | kNumPayloadTypes); |
| 423 | LOG(INFO) << "Uploading " << utils::ToString(payload_type) |
| 424 | << " for metric " << metric; |
| 425 | |
| 426 | metric = metrics::kMetricSuccessfulUpdateAttemptCount; |
| 427 | system_state->metrics_lib()->SendToUMA(metric, |
| 428 | attempt_count, |
| 429 | 1, // min: 1 attempt |
| 430 | 50, // max: 50 attempts |
| 431 | 50); // num_buckets |
| 432 | LOG(INFO) << "Uploading " << attempt_count |
| 433 | << " for metric " << metric; |
| 434 | |
| 435 | metric = metrics::kMetricSuccessfulUpdateUpdatesAbandonedCount; |
| 436 | LOG(INFO) << "Uploading " << updates_abandoned_count |
| 437 | << " (count) for metric " << metric; |
| 438 | system_state->metrics_lib()->SendToUMA(metric, |
| 439 | updates_abandoned_count, |
| 440 | 0, // min: 0 counts |
| 441 | 49, // max: 49 counts |
| 442 | 50); // num_buckets |
| 443 | } |
| 444 | |
| 445 | } // namespace metrics |
| 446 | |
| 447 | } // namespace chromeos_update_engine |